As is well known, a wrench is a hand tool used for holding and turning elements such as nuts, pipes, spark plugs, and the like. There are many kinds of wrenches, including monkey wrenches, single-ended wrenches, double-ended wrenches, box wrenches, and the like. Two common wrenches are the socket wrench which combines an offset handle with a male drive piece having a spring-loaded bearing lock on various sized sockets, and a ratchet wrench which is a socket wrench having a ratchet mechanism which controls the direction of applied torque.
Wrenches are used by mechanics in all sorts of applications, and in all sorts of conditions. For example, an automobile mechanic may e required to apply a ratchet wrench to various elements in an automobile engine. However, if such elements are in difficult-to-reach locations, proper application of torque can be difficult. This problem is especially apparent if the ratchet wrench is not long enough to properly reach the desired element.
Heretofore, it has not been possible for a hand tool such as a wrench to be easily extended to the precise length required for a particular job. Either the tool could not be extended far enough or it could only be extended to a length which was so great that the extended tool was either too cumbersome to use in an efficient manner or could not properly fit into the work space available.
Therefore, there is a need for an extension unit which can be used on a hand tool, especially on a socket or ratchet wrench, to efficiently extend the reach of such hand tool to a length which is exactly what is required for a particular job.